1. Field of the Invention
Hyaline membrane disease is caused in part by inadequate synthesis of surface-tension lowering material (surfactant) by the lung. The neonatal hyaline membrane disease represents a major cause of perinatal mortality. It is therefore desirable to have a simple and rapid test which would permit a determination of lung maturity by determining surfactant lipid presence in amniotic fluid, the results of which would provide a reliable indication of the neonatal pulmonary maturity. Desirably, the test should be simple, rapid, and provide results which are easy to interpret.
2. Description of the Prior Art
In 1972, Clements and co-workers introduced the amniotic fluid foam stability test for assessing fetal pulmonary maturity. Clements, et al., N.E.J.M. 286, 1077 (1972). The test employed a 0.475 ethanol volume fraction in a 1:1 volume ratio of amniotic fluid and 95% ethanol. In 1973, Edwards and Baillie modified the Clements' test to provide for 50 volume percent ethanol with a 1:1 ratio of amniotic fluid and 100% ethanol. Edwards and Baillie, S. Afr. Med. J. 47, 2070 (1973). Both the Clements and Edwards and Baillie tests rely on combining the ethanol with a predetermined amount of the amniotic fluid, shaking the mixture, and observing whether a stable foam is obtained. The two tests have received mixed reviews in the literature and there have been differences as to the reliability of the tests. See, for example, Myers et al., Am. J. Obstet. Gynecol. 121, 961 (1975); Statland et al., Am. J. Clin. Pathol. 69, 514 (1978).
The subject invention has been described at an annual meeting of the Society of Gynecological Investigation; Atlanta, Ga., Mar. 15-18, 1978.